1. Field of Invention
The present invention relates to a water treatment method which utilizes ozone for the water treatment process.
2. Description of Related Arts
Ozone is a strong oxidizing agent and is widely used in drinking water and sewage processing. However, ozone is quite selective on oxidation and degradation of organic substances. Catalytic ozone oxidation technology is an advanced oxidation processing technology in recent development in which ozone is used to produced highly oxidative hydroxyl radicals (.OH) under catalytic reaction. Compared to ozone-only mechanism, the hydroxyl radicals produced under catalytic reaction can oxidize organic substances non-selectively and the reaction is rapid and efficient. Accordingly, catalytic ozone oxidation technology becomes the hotspot of research and development at international level. Hydrogen peroxide (H2O2) catalyzes ozone mainly by the HO2− released from ionization of hydrogen peroxide in aqueous solution to induce the decomposition of ozone to produce the hydroxyl radicals. However, the treatment process which utilizes catalytic ozone oxidation with hydrogen peroxide has the following drawbacks in practice: (1) ionization of hydrogen peroxide is not easy by itself and therefore the ability to induce the decomposition of ozone is weak; (2) the residual hydrogen peroxide will require a large additional amount of chlorine in the subsequent disinfection process; (3) the hydrogen peroxide itself will reduce the number of free radicals (.OH+H2O2→H++O2−.), therefore in practice, a multi-points addition method is employed for the treatment process, which is very inconvenience to operation and management; (4) hydrogen peroxide in aqueous solution is highly unstable and easily decomposed, which is very inconvenience for storage and transportation.